Photographic developing tank



S p 2, 1952 R. SPAULDING 2,608,923

PHOTOGRAPHIC DEVELOPING TANK Filed Feb, 2, 1949 INVENTOR. LYMAN R. SPAULD/IVG Patented Sept. 2, 1952 UNITED STATES PATENT OFFICE :PHOTOGRAPHIC DEVELOPING TANK I I 'LymanR. Spauldingt Portland, Greg.

hpplication'Februaryfi, 1949, Serial No. 74,165

g .6 Claims. (01. .95 90,.5;) {Granted under the act of March 3, 11883, :as

The invention described herein may be manu- "jfactured and" used by or for the Government of theUnited "States for governmental purposes :withont the payment to me of any royalty there- 'on'in 'accordance'with the; provisions of the act ofAprili 30, 1928 (ch/460, 45 Stat. L. 467). Thisinvention isirelated to the processing of photographic film'ioll'owingexposure. In particularthisinvention isconcern'ed with tank developmentof moving picture film.

There are many photographic film developing jtanjks known in the art of photography in gen- ;eral, and presumably also in that .ofmovingpicturephotographyin particular. This invention fhas in common with other development 'tanks somefundamental features but :it" is a novel tank intended particularly for use'when short runs of movingwpicture film are required for examination immediately after exposure, or at any time without disturbing the camera or unexposed film.

A principal object of this'inventi'on isto pro- '.vide a'film developing tank that can serve first :as a receiver "for exposed film "as it "isxfed from the camera, storing a considerable number of ifeet, andthen serving asadeveloping tank when "the contained film has been detached from the camera.. Another vobjectis to provide in a tank of this kind arrangements for detaching the film from the remainder of film in the camera. without disturbing the camera and without riskf'ing exposure of .any of the film to stray light. A third objectis to provide arrangementsifor in- "tro'ducing developing chemicals into the tank without opening the tank and without'accidental admission of light. Another object is to provide arrangements for attaching the tank to an associated, camera and detaching .it conveniently without dangerof'leakage of light either into the camera or into the tank. Still another object is topprovide suitable processing of film including agitation thereof in the tank during the devel- .opment.

What constitutes this invention is "setforth in the following. specification in reference to the attached drawing and is succinctly defined inithe appended claims.

In the drawing, Figure '1 is 'a'view'in vertical "side elevation showing the interior of the opened developing tank in apreferred iormof embodiment as'attached to a. conventional -moving picture camera. Figure 12 is a 'vertical'si'de elevation of the tank of Figure 1 showing also insec- :tion part.'of the opening through which film enters the tank. FigureB .is inmo're detail showing the film admission opening including means for amended April 130, 1928; 370 O. G. 757) edge.

35 ure 5.

"to a rotating piece Hi'to which are attached Itwo fingers Hand 18.

cutting the filmand closing "the'opening. Figure 4 is a rear elevational View, pa-rtlyin section, of

part of the the film cutting'means shown in'Fig- 'ure'3, the sectional detail being 'taken-alongithe line 4-4 shown in Figure 3. Figure 5 :shows -in elevation part of the means provided for admittingchemicals to the tank, and the'means for agitating the film during development.

In Figure 1 a round shallow container or'tan'k l is provided at the periphery-with afil'm -gate comprising in part alight valve and film cutter housing 2. A similar and mating housing 3 is provided and attached to a conventionalcamera.

Inside camera 4, in lieu of the usual film'takeup reel, there is provided a special film chute v5 which guides the film 6 into housing '3. A

bracket 1 and clamping nut 8 are provided :for

holding the tank I and the attachments in place on camera 4.

Tank l in Figure 1 is shown open withoutrthe cover in place. The tank cover 9 is shown in Figure 2. The partial section in Figure -2 is taken through the film cutter h'ousingiZ. Cover 9 is preferably fittedtotank l'tby'threads'atthe Cover '9 is equipped with manipulative means, including an operating crank HI and a crank positioning lever 11. Also on cover!) there are two light-tight vents l2 and 13 provided one 2,, the .film will bereadily directed'intotank I and between fingers I! and I8.

In addition to the rotation of crank l0, the bearing in which crank l0 rotates is carr'ie'd'in .a disc .Zl, shown in plan in Figure ,2. heldin a circular channel formed under a retaining ring p.22.

Disc 2l and crank I'D together with fingers l! and 4-8 are arranged to rotate under retain- ..ing. ring 1.22 through an angle of the order of 90 degrees. "This rotation is limited'by lever l'l arranged to engage crank 10 in the two extreme positions. "In one positionfingers l1 and l B-are positionedunder the opening in housing 2, and

- opening between housing 2 and tank I.

guidance of the film assists in threading the,

3 in the other position, fingers I1 and I8 are placed nearer the center of tank I.

This is to provide for first receiving the film and afterward for moving the film as a whole toward the center of the tank and for rotating the film for agitation in the developing procedure.

Referring to Figure 2 and to Figure light is prevented from entering tank I through openings I4 and I5 by providing inside vents I2 and I3 a plurality of bafiies 23 each with a hole displaced as much as possible from the holes in the adjacent baiiies. plastic material so that reflection of light from one baflie to the next will be a minimum. This arrangement permits developing liquid. to be The bafiies 23 are made of black poured into and out of tank I through vents I2 and I3 without exposing the film therein to unwanted light.

Mechanical details of film cutter housing 2 are shown in Figures 3 and 4.. The housing has a thin slot 24 dimensioned to admit the film. In the housing a cylinder 25 is fitted similarly to the inside of a shut-01f valve. Cylinder 25 is retained by athreaded bushing 26, and is provided with a handle 21. The edges of cylinder 25 and of the inside of the bore 28 in housing 2 are made sharp so that when cylinder 25 is rotated the film in the housing is cut while at the same time light is prevented from entering the tank. 'Ihemating housing 3 attached to camera 4 is similar in principle to housing 2 and the parts therein. The functions and operation of housing 3 are the same as for housing 2, except that housing 3 is provided to protect the film in the camera 4 while housing 2 protects the film in the tank I. The film is usually cut by cutter in housing 3 which also seals the camera from light. The film is then drawn into the tank by turning disk 2I and crank ID. The cutter arm 21 on the tank is closed to seal the tank. This prevents a short piece of film being left to clog the slot 24.

Inside tank I there is a film guide and deflector 29 provided to deflect the film after passing first between fingers I! and I8 as described above.

The shape of guide 29- is as shown. This shape deflects the end of the film downward to the bottom of tank I where the film coils into a roll as the camera 4 feeds the film into tank I.

When the film is fed into tank I through housing 2, the film is guided toward fingers I1 and I8 by that portion of guide 29 nearest the film This film between the two fingers I1 and I8. As the film is fed farther into the tank I, the leading end of the film follows around the inside wall of the tank. If guide 29 were not there, the leading end of the film would follow the inside wall of tank I around until the end of the film was in contact with that portion of the film between housing 2 and fingers I 'I and I8. The leading end of the film would then follow the other portion of the film down between fingers I1 and I8. This is not desired because more than one thickness of film between fingers I1 and I8 can cause binding and interference with film movement With guide 29 in place the leading end of the film follows the inside wall of the tank around until the left hand end of guide 29 as shown in Figure 1 is encountered. This deflects the leading end of the film downward, bending the film away from the upper wall of tank I, and causing the film to pass between finger I1 and the center of the tank. With further feeding of with the disk 2| and the fingers I1 and I8 properlypositioned under the film slot 24. The housing 2 is placed in mating contact with housing 3 and the assemblage is secured in place by nut 8. When in place the light valves in housings 2 and 3 are opened by movement of lever 21 and a corresponding lever 3| on housing 3. The film 6 is directed through film chute 5 and through housings 3 and 2 into tank I where fingers I'I andIS have been properly positioned by lever II and hook I9 to receive the film.

After exposure, lever 3| is shifted to cut the film and close the light valve. Disk 2I is turned about and crank I I] is turned to draw film end into tank. The rotation of disc 2I moves the assemblage comprising crank I0, rotating piece I6, fingers I I and I 8, and hook I9 from the location near film guide 29 which is relatively close to the inside wall of the tank I to a location farther from the tank wall. The latter location is used to give the film held between fingers I1 and I8 room to follow around the fingers, when they are rotated, without crowding the film against the side of the tank. This is important to avoid toosharply bending and possibly scratching the film when handle I0 is reversed after having been rotated several revolutions in either direction. Then lever 21 is shifted to close the tank from light. The tank I is then released by nut 8 and removed. Crank I0 is then released from hook I9. Developing liquid is poured into tank I throughvent I2 or I3. The film is then manipulated by rotating crank I0 first in one direction until the film is completely wound around the outside fingers I! and I8. After a pause it is rotated in the opposite direction to expose the film fully and uniformly to the developing solution. After another pause the crank is reversed again, this operation being repeated several times depending on the developing time required, by the solution. After developing, washing and. fixing solutions are poured into the tank and the manipulation is continued as described.

I claim: y

l. A film developing tank comprising a cylindrical container having means for admitting film, said means including an elongated narrow slot, film agitating means comprising a pair of spaced fingers mounted to be rotated around an axis between them, a crank extending outside said container and connected to said fingers to cause said rotation, said axis being parallel to said slot, said fingers and crank being supported on a rotating disc mounted in fixed relation to said container and arranged so the axis of said crank can be moved within a range of locations in said container, and positioning means mounted in fixed relation to said container and arranged to releasably engage said crank and establish the space between said fingers in line with said slotfor admitting film to said container and between said fingers.

2. A film developing tank comprising a fiat cylindrical container. having a light-tight film gate including an elongated slot and means for cutting film entering said container, film agitating means extending within said container adjacent to said gate and including a pair of spaced fingers mounted to extend substantially parallel to said slot and also mounted to be rotated about a common axis substantially parallel to said slot, said fingers also being mounted in a movable section of said container to be displaced in a direction substantially at right angles to the axis of said cylindrical container within said container and having one position in which the space between said fingers is aligned with said slot, and a bent strip on the inner periphery of said container for deflecting and directing film away from said fingers.

3. In a film developing tank, the combination of a tank having a film entrance gate including an elongated slot, a pair of spaced spindles extending into said tank parallel with said slot and mutually rotatable about a common axis, said spindles being mounted in a rotatable section of the tank, crank means mounted externally of the tank and connected to at least one of said spindles to cause said mutual rotation, the arrangement being that said spindles are movable, by rotating said section of the tank, from a position near said gate and with the space between said spindles in alignment with said slot for receiving film, to a position nearer the center of said tank for film development, and means attached to the inside of said tank for deflecting the end of a film coiled in said tank, toward the center of said tank and away from said spindles.

4. A film developing tank comprising a fiat cylindrical container having a light-tight film gate with an elongated slot arranged to direct film through said slot into said container along an initial path so that the film will coil within the tank, cutting means associated with said gate, film agitating means including a pair of closely spaced fingers extending into said container parallel with said slot and mounted for mutual rotation about an axis, crank means mounted externally of the container and connected to at least one of said spindles to cause said mutual rotation, rotatable means for mounting said agitating means within the container so that said agitating means has at least two alternate positions, said film agitating means in one position being adjacent said gate with the space between said fingers in line with said initial path to receive the film between the fingers as it enters said container, guide means fixed to the inside entering between said fingers as the film coils within the container, said film agitating means in another position being substantially removed from the wall of the container to allow ample room for agitation of the film.

5. In a film-developing tank the combination of a film gate in the side of said tank, said gate including an elongated slot, a pair of spaced finger-like, narrow, rounded projections in said tank and parallel to said slot arranged to be mutually rotated about an axis parallel and close to one of the projections, a shaft, a bearing, and a crank outside said tank for rotating said projections, a movable segment in the top of said tank support ing said bearing and arranged to be shifted between two prescribed positions so said projections occupy alternatively a position near said film gate and a position nearer the center of said tank, and means attached to said tank for setting the rotational position of said projections in said position near said gate so that the space between said projections is aligned with said slot and so that film entering said tank through said gate is directed between said projections.

6. In a film-developing tank as described in claim 5, the combination of elements thereof and a projection on the inside periphery of said tank and adjacent said film gate arranged to deflect the end of a film following the inside wall of said tank away from said wall to prevent said end of film from passing a second time between said projections.

' LYMAN R. SPAULDING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,840,427 Barnack Jan. 12, 1932 1,889,818 Beidler Dec. 6, 1932 1,893,092 Liberman Jan. 3, 1933 1,921,012 Stevens et a1 Aug. 8, 1933 2,203,963 Lange June 11, 1940 2,359,611 Bolsey Oct. 3, 1944 2,403,717 Harvey July 9, 1946 

